My 2003 has been running great and all of a sudden it will not idle. Starts and runs at higher RPM but dies when I let off gas. Am getting P0108 code and also P0101 pending code. I replaced MAP sensor and no change. Darn. $70 bucks down the drain. Any suggestions?

for the P0101 Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4.0 seconds.

The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:

Inspect for the following conditions:
An incorrectly routed harness--Inspect the harness of the MAF sensor in order to verify that it is not routed too close to the following components:
- The secondary ignition wires or coils
- Any solenoids
- Any relays
- Any motors
A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor g/* display on the scan tool to increase rapidly. This increase should be from 6-12 g/* at idle to 230 g/* or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
The barometric pressure (BARO) that is used in order to calculate the predicted MAF value is initially based on the MAP sensor at key ON.
When the engine is running the MAP sensor value is continually updated near WOT. A skewed MAP sensor will cause the calculated MAF value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition ON and the engine OFF, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.
A high resistance on the ground circuit of the MAP sensor can cause this DTC to set.
Any loss of vacuum to the MAP sensor can cause this DTC to set.

This is for the p0101

check these out
https://www.gmforum.com/showthread.p...78#post1390964
https://www.gmforum.com/showthread.p...74#post1390960

Nothing has really changed under the hood so I do not suspect a wire routing issue. Vehicle really not driveable, put in gear and kills.

Well hense the two codes you have i suggest doing the tests for each code to rule out all possibiltys

Unplug your MAF. The engine will stumble and you will get a SES light for it. But the engine should smooth out and then run right. If that is the case, the MAF is bad. But if there is no change after a bit, the MAF is OK. The car can be driven without a MAF. Just don't get on the gas real hard.

Rest of the story. When I put in the MAP I started once maybe twice and it would not idle. The car was still in town. Went back in to drive the car home planning on keeping foot on the gas and kicking car into nuetral at stop signs to keep it running. Got about 1/4 mile down road and car started running just fine. Cleared codes and still fine. Maybe it took just a bit for new MAP to settle in or problem will be back.

With the engine idling, tap on top of the MAF. If the engine stumbles, the MAF is flaky.